The political “war on science” has come full circle: In claiming massive voter fraud in the presidential election, President Trump is effectively questioning political science.

Similar fraud charges previously have been debunked by academic studies, and the president’s claim that several million illegal immigrants voted last year — denying him a popular majority over Hillary Clinton — is discredited by a study released last month by a Dartmouth College team.

Will the study of politics, a social science, become as politicized as that of climate science and other “hard’’ sciences?

“That’s a good analogy,’’ Michael Herron, the Dartmouth government professor who co-authored the report, said this week. “We approached this as a science problem involving statistical analysis of elections. We weren’t working for anyone. We think this sort of study should be performed after every national election.’’

Writing after the election on Twitter, Trump claimed that 2 million to 3 million illegal immigrants had voted. He repeated the claim in a meeting this week with congressional leaders, this time setting the number at 3 million to 5 million. He also announced plans on Twitter for a federal investigation into “VOTER FRAUD’’ that would focus on “those registered to vote in two states, those who are illegal (and) … those registered to vote who are dead (and many for a long time).”

This did not sound like good news to many teachers of political science, who labor as it is to get students to support assertions with evidence.

Trump’s example “makes my job harder,’’ said Aaron Weinschenk, who teaches undergraduate courses in politics and government at the University of Wisconsin-Green Bay. “People talk about a ‘post-truth’ era. Not in my classroom. If you say something, you’re gonna need the evidence to back it up.’’

David Caputo, a political scientist and president emeritus of Pace University in New York, worked for several decades at the News Election Service, which collected raw election data for the major TV networks and news services. He noted that state secretaries of state, who supervise elections, do not subscribe to fraud charges. (Their national association has said it was “not aware of any evidence’’ supporting Trump’s charge.)

Caputo said the fact that local and county election officials, most of whom are Republicans, are not always quick to purge the dead from their rolls does not mean people are surging to the polls to impersonate them.

But he was philosophical.

“It’s not the first time the discipline has been attacked. People will continue to do their research, but (Trump’s claim) does reinforce the stereotype of leftists trying to inculcate our students. If you say something often enough, people begin to believe it.’’

President Trump hosts a reception for House and Senate leaders in the the State Dining Room of the White House on Jan. 23, 2017.(Photo: Susan Walsh, AP)

Science became increasingly politicized, largely over global warming, during the administration of President George W. Bush. In his inaugural address eight years ago, Barack Obama pledged to “restore science to its rightful place.’’

In 2015, Obama signed an executive order promoting the use of behavioral science data in government policy and programs and created a “social and behavioral insights team’’ to work on projects such as savings plans for military service members and college enrollment by low-income students.

Trump’s claims about the election results suggests he has no such regard for social science. In his tweet this week announcing the plans for an election study, he wrote: “Depending on results we will strengthen up voting procedures!”

Trump provided no details. But one of his longtime supporters said he thought Trump wants to “eventually ensure 100% integrity of the vote.’’

“Is it really discriminatory,’’ asked Gene Dunn, a Long Island limousine driver, “to ask a person to show I.D. before casting a sacred ballot when we have to show I.D. for dozens of other less significant events?’’

Others see darker motives. Caputo said Trump’s move looks like a partisan attempt to suppress registration by people who’d be more likely to vote Democratic than Republican. Whatever Trump’s motive, the Dartmouth study makes clear there is no social scientific basis for his claim. “We do not uncover any evidence consistent with Trump’s assertions about widespread voter fraud,’’ it concluded.

The researchers also said they found no “striking abnormalities” in three states which had (anti-Trump) recount battles (Michigan, Pennsylvania and Wisconsin) or three cited by Trump himself (California, New Hampshire and Virginia).

Herron, the Dartmouth professor, said he and his two co-authors expected Trump to challenge the election results if he lost (although not if he won) and began preparing their study last summer. They hired two students to help crunch numbers and contracted with the Associated Press for voting data. Using statistical analysis, they created a baseline for the expected Trump vote across the country, relying heavily on Mitt Romney’s vote share from the 2012 election. But they found nothing to support Trump’s charges.

Herron was asked whether he was concerned about a broader politicization of social science.

He at first declined to answer. He’s a social scientist — where’s the data? Then he said: “It worries me as a citizen whenever people make claims without evidence.’’

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